异质结构在光伏型卤化物钙钛矿光电转换器件中的应用

Application of heterostructures in halide perovskite photovoltaic devices

钙钛矿材料由于具有长的载流子扩散长度、较高的吸收系数和较低的缺陷态密度等优点在太阳电池、光电探测器、发光二极管等光电转换器件领域得到广泛应用.同时,层状二维材料、低维半导体纳米结构、金属纳米结构和绝缘材料等功能材料因它们特殊的化学、电学和物理性质而越来越受到人们的关注.为了拓宽钙钛矿材料在光电转换器件的应用,可将钙钛矿与这些功能材料进行组合,形成异质结构,集成两种材料的优点.钙钛矿/功能材料异质结构可作为界面修饰层、电荷传输层、封装层等应用于卤化物钙钛矿光电转换器件中,用来抑制光生载流子的复合损耗,提升载流子的传输性能,改善器件的稳定性等.本文综述了钙钛矿与层状二维材料、低维半导体纳米结构、金属纳米结构和绝缘材料等形成的异质结构在光伏型光电转换器件中应用的最新研究进展,并对该方向未来的发展做出了展望.

Perovskites are widely used in various kinds of optoelectronic devices,including solar cells,photodetectors,light-emitting diodes,etc.,due to their excellent properties such as long carrier diffusion length,high absorption coefficient,low trap state density and so on.Functional materials such as layered two-dimensional materials(graphene,transition metal dichalcogenides,etc.),low-dimensional semiconductor nanostructures(nanoparticles,quantum dots,nanowires,nanotubes,nanorods,nanopieces,etc.),metallic nanostructures(Au,Ag,etc.)and insulating materials(insulating polymer,organic amine,inorganic insulating film,etc.)have attracted more and more attention due to their special chemical,electrical and physical properties.In order to broaden the application of perovskites in photovoltaic devices,perovskites can be combined with various functional materials to form heterostructures so as to combine the advantages of the two types of materials.The heterostructures of perovskites/functional materials can be used as the interface modification layer in halide perovskites photovoltaic devices,to improve the crystallinity of perovskite,effectively reduce the surface defects and suppress the carrier recombination loss at the interface.The heterostructures of perovskites/functional materials can be used as the charge transporting layer in halide perovskites photovoltaic devices,can match well with the perovskite energy levels,which is beneficial to the efficient extraction of holes and electrons.The heterostructures of perovskites/functional materials also can be used as encapsulation layer in halide perovskites photovoltaic devices,to reduce the contact between water and perovskite,it can effectively prevent the degradation of perovskite,to improve the device stability.In addition,the semiconductor with narrow bandgap or array structure can be used to broaden the spectral response and to improve the light absorption of the perovskite photovoltaic devices.In a word,the heterostructures of perovskites/functional materials are applied to devices is an effective way to obtain high performance and low cost photovoltaic devices.In this review,recent works on the applications of the heterostructures in halide perovskite photovoltaic devices are comprehensively presented and discussed.The progress and advantages of the heterostructures as the interface modification layer,charge transporting layers and encapsulation layer in halide perovskite photovoltaic devices are systemically reviewed.Finally,we summarize the whole paper and give a prospect for the development of heterostructures based perovskite photovoltaic devices in the future.